Vector Inverter System

System composition
The inverter of the three-phase cage asynchronous motor drive system based on dual DSP vector control adopts AC-DC-AC voltage type structure and SVPWM pulse width modulation. The system consists of a three-phase rectifier, filter capacitor, voltage inverter, inverter drive circuit, three-phase cage asynchronous motor and dual DSP control system.
The dual DSP control system consists of three parts: VC33 subsystem, F240 subsystem and data exchange unit. Vector control is based on VC33 chip, which is used to complete the core algorithm of vector control and two-phase current detection. F240 mainly completes three-phase PWM waveform generation, motor speed measurement and overvoltage protection functions. The data exchange part uses dual-port RAM, which enables the two DSP chips to exchange data quickly and conveniently, enhancing the parallel processing capability of the dual DSP system.
System software
The system software consists of two parts, VC33 subsystem vector control software and F240 subsystem SVPWM control software.
Vector control contains a lot of mathematical operations, and the entire algorithm consists of multiple modules, such as coordinate transformation, flux calculation, speed regulation and torque current regulation modules. The control time of the current inner loop in this system is 50μs, and the speed outer loop is 400μs.
The F240 subsystem control software mainly completes the SVPWM waveform generation and motor speed measurement program. In order to achieve a good control effect, this system uses a voltage space vector, that is, a combination of six non-zero voltage vectors and two zero vectors to make the voltage vector as close to circular motion as possible. The pulse capture unit of this chip is used for speed measurement.